() { //使用匿名内部类创建Comparator对象，重写compare方法 @Override public int compare(Student o1, Student o2) { return o1.getBirthday().compareTo(o2.getBirthday()); } }); //遍历输出排序后的学生信息 for (Student s : students) { System.out.println(s.getId() + " " + s.getName() + " " + s.getBirthday()); } } //getters and setters public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getBirthday() { return birthday; } public void setBirthday(String birthday) { this.birthday = birthday; } }

楼主，以下是我的实现方式，看看是不是你想要的，哪里不清楚的可以单独M我。

```java import java.util.Arrays; import java.util.Comparator;

public class Student { private int id; private String name; private String birthday;

public Student(int id, String name, String birthday) { this.id = id; this.name = name; this.birthday = birthday; }

public static void main(String[] args) { Student s1 = new Student(1, "张三", "1983-01-22"); Student s2 = new Student(2, "张一", "1983-01-21"); Student s3 = new Student(3, "张笑一", "1983-01-27"); Student s4 = new Student(4, "张含一", "1983-01-01"); Student[] students = { s1, s2, s3, s4 }; //将4个学生对象装入数组中

//现根据出生日期对数组元素进行排序，由于String已经实现了Comparable接口，可以直接利用compareTo方法进行比较 Arrays.sort(students, new Comparator() { //使用匿名内部类创建Comparator对象，重写compare方法 @Override public int compare(Student o1, Student o2) { return o1.getBirthday().compareTo(o2.getBirthday()); } });

//遍历输出排序后的学生信息 for (Student s : students) { System.out.println(s.getId() + " " + s.getName() + " " + s.getBirthday()); } }

//getters and setters public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getBirthday() { return birthday; } public void setBirthday(String birthday) { this.birthday = birthday; } } ```